When Does Lake of the Woods Freeze? Ice-In Dates

Lake of the Woods usually locks up in late November to early December. The Minnesota DNR State Climatology Office has 11 ice-in reports on file for the lake. The earliest is November 16 (1984). The latest is December 6 (2025). The median of those 11 reports is November 28.

Ice-in is not the same as safe ice. It means the lake froze over and the cover stayed through winter, per the DNR's observer definition. First ice is thin. Thickness changes by the yard. No ice is ever 100% safe. Check it yourself.

The short answer

• Earliest ice-in on record: November 16, 1984.
• Latest ice-in on record: December 6, 2025.
• Median ice-in: November 28 (the DNR's figure, and the same result when we sorted the 11 reports ourselves).
• Spread: 20 days from earliest to latest.
• Hardwater season: the DNR says to fish the ice "early December to late March."

What this means for you: ice-in has come as early as mid-November, but most years it is late November or later. Walking on first ice needs at least 4 inches of new, clear ice, and you have to measure it.

What the record covers

The numbers come from the Minnesota DNR Lake Ice In map, run by the State Climatology Office. The data feed behind that map lists the lake under the name "Lake of the Woods." We did not find separate ice-in records for Baudette, Northwest Angle or Zippel Bay. So every date here is for the one record labeled "Lake of the Woods."

Here is how that record is built:

• Volunteer observers report the date the lake froze over and stayed frozen.
• The DNR holds 11 reports for this lake.
• The first report is from 1977. The most recent is from 2025.
• There are gaps. No reports are on file for 1978 to 1981, 1985 to 2017, or 2023.

Treat it as a small sample. Eleven reports are enough to show the usual window. They are not enough to promise any given year. The DNR map puts a marker on lakes whose period of record spans 20 or more years. This lake's record runs from 1977 to 2025, but with only 11 reports, so the median rests on a thin base.

Lake of the Woods ice-in dates by year

All dates are from the Minnesota DNR Lake Ice In data for the record named "Lake of the Woods." Years not listed have no report on file.

Median of the 11 reports: November 28. Method: we sorted the 11 dates by calendar day and took the sixth. The DNR lists the same median.

Recent years

The seven reports from 2018 to 2025 run from November 18 to December 6. Sorted, they are November 18, November 21, November 30, December 1, December 2, December 4 and December 6. The middle one is December 1. That is a few days later than the all-record median, but seven reports is a thin base. Do not read a trend into it.

The last two reports on file, 2024 (December 4) and 2025 (December 6), are the latest two in the whole table.

Ice-in is not ice-fishing ready

Locking up does not mean the lake is open for business. Two official sources give the usual timing for the hardwater season:

• The Minnesota DNR says: "Fish the ice early December to late March."
• The Lake of the Woods Tourism site says: "Around December 10 (varies by year), resorts place heated day houses over walleye and sauger schools."

That second date is a typical timing from the tourism bureau, not a promise. It varies by year. The same site notes plowed ice roads appear "some seasons." It also says: "Don't drill in ice roads." The posted speed limit on resort-maintained ice roads is 15 mph, per the same page.

Plowed road access depends on thickness and snow. We found no official record of the date roads open in each year, so we are not listing one.

About the lake

The DNR describes Lake of the Woods as a 951,337-acre lake. Nearly one third of it lies in Minnesota, which makes it the state's largest lake by the DNR's wording. The DNR also refers to the Ontario portion of the lake, and the Lake of the Woods Tourism site calls it a border water with Canada. That site describes Big Traverse Bay as stretching 30 miles north-south and 25 miles east-west. We did not find an official source comparing freeze-up dates between Big Traverse Bay and the shallower bays, so we make no claim about it. Do not assume one part of this big lake has the same ice as another. Wind, current and snow can leave thin spots anywhere.

Minimum ice thickness from the DNR

These are Minnesota DNR guidelines. They apply to new, clear ice only. The DNR says to double the thickness on white ice.

The DNR also warns that ice "can be two feet thick in one place and one inch thick a few yards away." One good reading is not the whole lake. Drill often. Measure each time.

Treat these as floors, not targets. Add a margin on a lake this size, where wind can shift ice and a long walk puts help far away.

How to check current ice

1. Call or check a local source before you go. The ice-in map does not post the current year's date in real time, per the DNR, because the cover may not hold.
2. Drill and measure. Use an ice auger and a tape or ice gauge. Check every few steps early in the season.
3. Look at the color. Clear ice is stronger than white or snow ice. Double the thickness on white ice.
4. Stay off pressure ridges, cracks, inlets and river mouths. Moving water thins ice from below.
5. Stay on marked and groomed routes if you drive. Do not drill in ice roads.
6. Carry ice picks, a rope and a float. Tell someone your route and your return time.
7. Walk, then ride, then drive. Step up only when thickness supports the next step.

When it locks up for good vs. first ice

The ice-in date is the day observers say the lake froze over and stayed frozen. First ice can form earlier in sheltered spots and then open up again with wind or a warm spell. That is why a calendar date should never stand in for a measurement. A cold snap in mid-November can give you a skim of ice on a bay that is gone by the weekend.

For context, the DNR also keeps ice-out records. For Lake of the Woods, the DNR ice-out table lists an earliest date of April 8, 2012, a median of May 3 and a latest of May 21, 2014. That is the other end of the season. Those are ice-out dates, a separate record from ice-in.

Bottom line

Expect Lake of the Woods to lock up from mid-November at the earliest to early December at the latest, with late November the middle of the road. Then give it time to thicken. Use the DNR minimums, measure the ice yourself, and treat any date as a rough guide only.

No ice is ever 100% safe. Check it yourself.

FAQ

When does Lake of the Woods usually freeze?

Late November to early December. The DNR median ice-in date, from 11 reports, is November 28.

What is the earliest Lake of the Woods has frozen?

November 16, in 1984, in the Minnesota DNR record. The latest on record is December 6, in 2025.

When does ice fishing start on Lake of the Woods?

The DNR says to fish the ice from early December to late March. The tourism bureau says heated day houses go out around December 10, and that varies by year.

How thick does ice need to be to walk on?

The DNR says at least 4 inches of new, clear ice for foot travel. Snowmobiles and small ATVs need 5 to 7 inches. Double it for white ice.

Does an ice-in date mean the ice is ready?

No. It only means the lake froze and stayed frozen. Thickness still has to be measured. No ice is ever 100% safe. Check it yourself.